Remove trailing whitespace and clean up comments

12/Keyboard.jack

@@ -10,7 +10,7 @@ class Keyboard {
     /** Initializes the keyboard. */
     function void init() {
         return;
-    } 
+    }
 
     /**
      * Returns the character of the currently pressed key on the keyboard;
@@ -37,35 +37,30 @@ class Keyboard {
     }
 
     /**	Waits until a key is pressed on the keyboard and released,
-     *  then echoes the key to the screen, and returns the character 
+     *  then echoes the key to the screen, and returns the character
      *  of the pressed key. */
     function char readChar() {
         var char key;
-        
+
         // Wait for key press
         while (Keyboard.keyPressed() = 0) {}
-        
+
         let key = Keyboard.keyPressed();
-        
+
         // Wait for release
         while (~(Keyboard.keyPressed() = 0)) {}
-        
+
         // Echo (except backspace)
         if (key < 129) {
              // Handle newline specially for cleaner output?
-             // Output.printChar(128) might not do NewLine with my Output implementation unless I updated it?
-             // My Output implementation (Step 240) does NOT check for 128.
-             // So I should call println() if 128.
              if (key = 128) {
                  do Output.println();
              } else {
                  do Output.printChar(key);
              }
         }
-        // If key > 129 (arrows etc), printChar might print garbage or square. 
+        // If key > 129 (arrows etc), printChar might print garbage or square.
-        // Spec usually implies echoing everything or being selective.
+
-        // I'll stick to echoing only standard chars + newline.
-            
         return key;
     }
 
@@ -75,24 +70,24 @@ class Keyboard {
     function String readLine(String message) {
         var String s;
         var char c;
-        
+
         do Output.printString(message);
         let s = String.new(64); // Assume max line 64
-        
+
         while (true) {
             let c = Keyboard.readChar();
-            
+
             if (c = 128) { // Newline
                 do Output.println();
                 return s;
             }
-            
+
             if (c = 129) { // Backspace
                 if (s.length() > 0) {
                     do s.eraseLastChar();
                     do Output.backSpace();
                     // Erase not supported by Output, so we print space and back up again?
-                    // But printChar sends cursor forward. 
+                    // But printChar sends cursor forward.
                     // To visually erase: Backspace (move left), Print Space (overwrite, move right), Backspace (move left).
                     // My output implementation doesn't support 'erasing' naturally.
                     // But this trick works.
@@ -104,7 +99,7 @@ class Keyboard {
             }
         }
         return s;
-    }   
+    }
 
     /** Displays the message on the screen, reads from the keyboard the entered
      *  text until a newline character is detected, echoes the text to the screen,
@@ -113,11 +108,11 @@ class Keyboard {
     function int readInt(String message) {
         var String s;
         var int val;
-        
+
         let s = Keyboard.readLine(message);
         let val = s.intValue();
         do s.dispose();
-        
+
         return val;
     }
 }

12/Output.jack

@@ -5,18 +5,18 @@
 /**
  * A library of functions for writing text on the screen.
  * The Hack physical screen consists of 512 rows of 256 pixels each.
- * The library uses a fixed font, in which each character is displayed 
+ * The library uses a fixed font, in which each character is displayed
- * within a frame which is 11 pixels high (including 1 pixel for inter-line 
+ * within a frame which is 11 pixels high (including 1 pixel for inter-line
  * spacing) and 8 pixels wide (including 2 pixels for inter-character spacing).
  * The resulting grid accommodates 23 rows (indexed 0..22, top to bottom)
- * of 64 characters each (indexed 0..63, left to right). The top left 
+ * of 64 characters each (indexed 0..63, left to right). The top left
  * character position on the screen is indexed (0,0). A cursor, implemented
  * as a small filled square, indicates where the next character will be displayed.
  */
 class Output {
 
     // Character map for displaying characters
-    static Array charMaps; 
+    static Array charMaps;
     static int cursorRow, cursorCol;
 
     /** Initializes the screen, and locates the cursor at the screen's top-left. */
@@ -29,9 +29,9 @@ class Output {
     // Initializes the character map array
     function void initMap() {
         var int i;
-    
+
         let charMaps = Array.new(127);
-        
+
         // Black square, used for displaying non-printable characters.
         do Output.create(0,63,63,63,63,63,63,63,63,63,0,0);
 
@@ -52,9 +52,9 @@ class Output {
         do Output.create(43,0,0,0,12,12,63,12,12,0,0,0);     // +
         do Output.create(44,0,0,0,0,0,0,0,12,12,6,0);        // ,
         do Output.create(45,0,0,0,0,0,63,0,0,0,0,0);         // -
-        do Output.create(46,0,0,0,0,0,0,0,12,12,0,0);        // .    
+        do Output.create(46,0,0,0,0,0,0,0,12,12,0,0);        // .
         do Output.create(47,0,0,32,48,24,12,6,3,1,0,0);      // /
-        
+
         do Output.create(48,12,30,51,51,51,51,51,30,12,0,0); // 0
         do Output.create(49,12,14,15,12,12,12,12,12,63,0,0); // 1
         do Output.create(50,30,51,48,24,12,6,3,51,63,0,0);   // 2
@@ -65,7 +65,7 @@ class Output {
         do Output.create(55,63,49,48,48,24,12,12,12,12,0,0); // 7
         do Output.create(56,30,51,51,51,30,51,51,51,30,0,0); // 8
         do Output.create(57,30,51,51,51,62,48,48,24,14,0,0); // 9
-        
+
         do Output.create(58,0,0,12,12,0,0,12,12,0,0,0);      // :
         do Output.create(59,0,0,12,12,0,0,12,12,6,0,0);      // ;
         do Output.create(60,0,0,24,12,6,3,6,12,24,0,0);      // <
@@ -132,7 +132,7 @@ class Output {
         do Output.create(120,0,0,0,51,30,12,12,30,51,0,0);     // x
         do Output.create(121,0,0,0,51,51,51,62,48,24,15,0);    // y
         do Output.create(122,0,0,0,63,27,12,6,51,63,0,0);      // z
-        
+
         do Output.create(123,56,12,12,12,7,12,12,12,56,0,0);   // {
         do Output.create(124,12,12,12,12,12,12,12,12,12,0,0);  // |
         do Output.create(125,7,12,12,12,56,12,12,12,7,0,0);    // }
@@ -163,7 +163,7 @@ class Output {
 
         return;
     }
-    
+
     // Returns the character map (array of size 11) of the given character.
     // If the given character is invalid or non-printable, returns the
     // character map of a black square.
@@ -180,14 +180,6 @@ class Output {
         let cursorRow = i;
         let cursorCol = j;
         return;
-        // Spec says "and erases the character displayed there"?
-        // Usually moveCursor just moves it. The cursor 'character' itself (black square) 
-        // is typically implemented by blinking or drawing.
-        // Project 12 spec: "A cursor, implemented as a small filled square, indicates where the next character will be displayed."
-        // And "erases the character displayed there"? Maybe erases the *cursor* from old location?
-        // Or erases the *content*? "Erases the character displayed there" usually implies drawing black square (cursor) or clearing it?
-        // Wait, standard implementation usually just updates coordinates.
-        // I will assume simple update.
     }
 
     /** Displays the given character at the cursor location,
@@ -195,18 +187,18 @@ class Output {
     function void printChar(char c) {
         var Array map;
         var int i, val, address;
-        
+
         let map = Output.getMap(c);
         let address = 16384 + (cursorRow * 352) + (cursorCol / 2);
-        
+
         let i = 0;
         while (i < 11) {
             let val = map[i];
-            
+
             // Apply val to screen
             // If col is even, left byte (bits 0-7). If odd, right byte (8-15).
             // LSB is left.
-            
+
             if ((cursorCol & 1) = 0) { // Even col
                 // Mask out low byte (0x00FF), keep high byte
                 // Keep high byte: value & -256 (0xFF00)
@@ -218,12 +210,12 @@ class Output {
                 // Set high byte: val << 8
                 let val = (Memory.peek(address + (i * 32)) & 255) | (val * 256);
             }
-            
+
             do Memory.poke(address + (i * 32), val);
-            
+
             let i = i + 1;
         }
-        
+
         // Advance cursor
         let cursorCol = cursorCol + 1;
         if (cursorCol > 63) {
@@ -233,7 +225,7 @@ class Output {
                 let cursorRow = 0; // Wrap to top?
             }
         }
-        
+
         return;
     }
 

12/Screen.jack

@@ -5,13 +5,13 @@
 /**
  * A library of functions for displaying graphics on the screen.
  * The Hack physical screen consists of 512 rows (indexed 0..511, top to bottom)
- * of 256 pixels each (indexed 0..255, left to right). The top left pixel on 
+ * of 256 pixels each (indexed 0..255, left to right). The top left pixel on
  * the screen is indexed (0,0).
  */
 class Screen {
     static boolean color;
     static Array powersOfTwo; // Helper for bit manipulation
-    
+
     /** Initializes the Screen. */
     function void init() {
         let color = true; // Default black
@@ -57,20 +57,19 @@ class Screen {
     function void drawPixel(int x, int y) {
         var int address, value;
         var int mask;
-        
+
         let address = 16384 + (y * 32) + (x / 16);
         let value = Memory.peek(address);
-        
+
-        // Calculate 2^(x%16) logic inline or helper? 
         // x & 15 is x % 16
-        let mask = powersOfTwo[x & 15]; 
+        let mask = powersOfTwo[x & 15];
-        
+
         if (color) {
             let value = value | mask;
         } else {
             let value = value & ~mask;
         }
-        
+
         do Memory.poke(address, value);
         return;
     }
@@ -81,7 +80,7 @@ class Screen {
         var int a, b;
         var int diff;
         var int temp;
-        
+
         if (x1 > x2) {
             let temp = x1;
             let x1 = x2;
@@ -90,13 +89,13 @@ class Screen {
             let y1 = y2;
             let y2 = temp;
         }
-        
+
         let dx = x2 - x1;
         let dy = y2 - y1;
         let a = 0;
         let b = 0;
         let diff = 0;
-        
+
         // Vertical line
         if (dx = 0) {
             if (y1 > y2) {
@@ -110,7 +109,7 @@ class Screen {
             }
             return;
         }
-        
+
         // Horizontal line
         if (dy = 0) {
            while (~(x1 > x2)) {
@@ -119,7 +118,7 @@ class Screen {
            }
            return;
         }
-        
+
         // Diagonal
         if (dy > 0) {
             while ((~(a > dx)) & (~(b > dy))) {
@@ -144,7 +143,7 @@ class Screen {
                 }
             }
         }
-        
+
         return;
     }
 
@@ -165,14 +164,14 @@ class Screen {
         var int dy;
         var int r2;
         var int halfWidth;
-        
+
         if (r > 181) {
             return; // overflow check
         }
-        
+
         let dy = -r;
         let r2 = r*r;
-        
+
         while (~(dy > r)) {
             let halfWidth = Math.sqrt(r2 - (dy*dy));
             do Screen.drawLine(x - halfWidth, y + dy, x + halfWidth, y + dy);

12/String.jack

@@ -19,10 +19,6 @@ class String {
     constructor String new(int maxLength) {
         if (maxLength = 0) {
             let maxLength = 1; // min length 1 for alloc safety?
-            // Actually spec says allocation of 0 size might happen. 
-            // My Array.new -> Memory.alloc handles 0 size by returning a 1 word block (header-1?? No).
-            // Let's alloc 0 if needed.
-            // If maxLength is 0, we can't really store anything.
         }
         if (maxLength > 0) {
             let buffer = Array.new(maxLength);
@@ -74,23 +70,23 @@ class String {
         return;
     }
 
-    /** Returns the integer value of this string, 
+    /** Returns the integer value of this string,
      *  until a non-digit character is detected. */
     method int intValue() {
         var int val, i, d;
         var boolean neg;
-        
+
         let val = 0;
         let i = 0;
         let neg = false;
-        
+
         if (length > 0) {
             if (buffer[0] = 45) { // '-'
                 let neg = true;
                 let i = 1;
             }
         }
-        
+
         while (i < length) {
             let d = buffer[i] - 48; // '0' is 48
             if ((d > -1) & (d < 10)) {
@@ -100,7 +96,7 @@ class String {
                 let i = length; // break
             }
         }
-        
+
         if (neg) {
             return -val;
         }
@@ -110,24 +106,24 @@ class String {
     /** Sets this string to hold a representation of the given value. */
     method void setInt(int val) {
         let length = 0; // Clear string
-        
+
         if (val < 0) {
             let val = -val;
             do appendChar(45); // '-'
         }
-        
+
         do int2String(val);
         return;
     }
-    
+
     // Helper for recursive int printing
     method void int2String(int val) {
         var int lastDigit;
         var int c;
-        
+
         let lastDigit = val - ((val / 10) * 10); // val % 10
         let c = lastDigit + 48;
-        
+
         if (val < 10) {
             do appendChar(c);
         } else {

12/Sys.jack

@@ -10,8 +10,11 @@ class Sys {
 
     /** Performs all the initializations required by the OS. */
     function void init() {
+        // do Memory.poke(8000, 1); // Start
         do Memory.init();
+        // do Memory.poke(8000, 2); // Mem init done
         do Math.init();
+        // do Memory.poke(8000, 3); // Math init done
         do Screen.init();
         do Output.init();
         do Keyboard.init();
@@ -35,10 +38,8 @@ class Sys {
              let j = 0;
              // Calibration: loop count determines delay.
              // On typical VM emulator settings (Fast), ~50-100 loops might be 1ms?
-             // User requested 2 seconds wait in test.
              // "WaitWithInput" sample in Snake used loop for waiting.
              
-             // Standard N2T value is roughly 50-100.
              while (j < 50) {
                  let j = j + 1;
              }